Pivots - Does bigger mean better?

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Jul 13, 2007
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So i guess this is the place to ask, i think.:)
With many knives available with large or oversized
pivot pins and pivot screws, etc, from many companies, there are just as many companies that do not offer folding knives with "heavy duty" pivot assemblies. Why or why not? The concept does seem sound enough to me to make the folder a bit stronger at it's weakest point. Does a bigger pivot on paper actually translate into a stronger or better knife??
 
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It does, to a point. Problem is, the weakness then moves to the next link in the chain.

For example, I had a $4 POS travel knife once. Snapped it in half, with the pivot completely pulling free of the scales. The pivot didn't fail, the scales did.
 

TheCarbideRat

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It does, to a point. Problem is, the weakness then moves to the next link in the chain.

For example, I had a $4 POS travel knife once. Snapped it in half, with the pivot completely pulling free of the scales. The pivot didn't fail, the scales did.

Exactly, as a chain is only as strong as it's weakest link. So a big pivot knife should theoretically have commensurate strength in it's other components, if not then the maker either doesn't know how to construct a sound knife or is just fronting his game.
 
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I agree with "as strong as it's weakest link. A folder with the same sized pivot in a steel lined or Ti handle will be stronger than one in an unlined plastic handle.
 
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So i guess this is the place to ask, i think.:)
With many knives available with large or oversized
pivot pins and pivot screws, etc, from many companies, there are just as many companies that do not offer folding knives with "heavy duty" pivot assemblies. Why or why not? The concept does seem sound enough to me to make the folder a bit stronger at it's weakest point. Does a bigger pivot on paper actually translate into a stronger or better knife??

I think that well though construction is more important than just a pivot size.
You can take a look on spyderco manix and Chinook I. They don't have big pivots but nobody reported problem with this part.

I believe that new overbuilt folders are designed to sell to directly to last longer.
 
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Aug 21, 2010
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What do they use for liners and what are the pins made of?


I'm not sure one can say bigger is better in general. A big plastic pivot would be weaker than a small ti pin, provided all else was equal and both had great liners. :)
 
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Aug 26, 2010
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Let's not get off track. All construction being equal, does a bigger pivot make that component stronger? The answer is Yes The same way a larger axle in a truck is stronger than a smaller axle.
 
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All the above plus another factor:

Does the folder use dual thumbstuds instead of a stop pin?
This design makes any pivot MUCH stronger. That is why Strider and Hinderer use the design.
 
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This is true as well. Its all basic physics. The thumb studs are farther down the blade and when they contact the stop points they are taking advantage of a longer fulcrum. The closer to the pivot point the stop pin is, the more force is transferred to the area. Its one of the reason the ZT knives are so tough.

All the above plus another factor:

Does the folder use dual thumbstuds instead of a stop pin?
This design makes any pivot MUCH stronger. That is why Strider and Hinderer use the design.
 

marthinus

Knifemaker / Craftsman / Service Provider
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I dont know. You barely hear of any pivots breaking these days on forums. Be it Al Mar to ZT.
 
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In line with the general consensus here, the pivot hole should be proportionate to the size of the tang too. So as the overall blade gets smaller, so too should the pivot. Otherweise the hole weakens the tang. I don't want a hole that almost deletes the tang itself.

But overall, I'm on board with the good design and well thought construction notion along with trust of a particular MFG or MFG's/makers . . .
 
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Idaho quote: "I think that well though construction is more important than just a pivot size.
You can take a look on spyderco manix and Chinook I. They don't have big pivots but nobody reported problem with this part."

A very good example indeed! If you look at a Manix or Chinook compared size wise to a knife with a large pivot like a Zt 300 series, i cannot help but wonder why a bigger pivot is not used by Spyderco here since these are fairly large knives designed for hard work. Would not these knives benefit fron a larger pivot assembly too?:confused:
...And don't get me wrong...i love the hell out of Spyderco...otherwise i would probably not own over fifty of them...:D
 
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Apr 21, 2009
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A larger pivot is stronger. Let's consider a thought experiment where we slowly and incrementally increase the pivot size. Eventually the pivot becomes large enough that there isn't enough metal around the pin to effectively anchor it. A balance must be struck by the designers WRT knife strength with this in mind. Marketing also plays a role, the more overbuilt and tactical a design appears to be the more it appeals to a large segment of the knife buying population that are enamored of all things "tactical". When a maker is deciding the diameter of the pivot that they are going to use they might also be considering the quality of the opening and lockup.

My instinct is that provided that the manufacturing tolerances and free-play of the pivot are independent of size, a larger pivot will allow for a greater degree of centeredness and the more parallel assembly should be able to operate with less wobble and the lockup ought to be made more secure as the blade stop, and blade should move less with respect to one another.

Also distributing the friction and wear across a greater surface area should mean, all other things being equal, that the parts wear more slowly.
 
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Idaho quote: "I think that well though construction is more important than just a pivot size.
You can take a look on spyderco manix and Chinook I. They don't have big pivots but nobody reported problem with this part."

A very good example indeed! If you look at a Manix or Chinook compared size wise to a knife with a large pivot like a Zt 300 series, i cannot help but wonder why a bigger pivot is not used by Spyderco here since these are fairly large knives designed for hard work. Would not these knives benefit fron a larger pivot assembly too?:confused:
...And don't get me wrong...i love the hell out of Spyderco...otherwise i would probably not own over fifty of them...:D

his point was that, to his knowledge, nobody reported any sort of problem with the small pivots on those knives.

So apparently their design, in that regard, is more than strong enough for their application.

If they are more than strong enough, why spend the additional money to needlessly "beef it up", which translates to a more expensive knife for us to buy?
 
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Althnough this is not my area of expertise, I agree with your statement. Good point.

A larger pivot is stronger. Let's consider a thought experiment where we slowly and incrementally increase the pivot size. Eventually the pivot becomes large enough that there isn't enough metal around the pin to effectively anchor it. A balance must be struck by the designers WRT knife strength with this in mind. Marketing also plays a role, the more overbuilt and tactical a design appears to be the more it appeals to a large segment of the knife buying population that are enamored of all things "tactical". When a maker is deciding the diameter of the pivot that they are going to use they might also be considering the quality of the opening and lockup.

My instinct is that provided that the manufacturing tolerances and free-play of the pivot are independent of size, a larger pivot will allow for a greater degree of centeredness and the more parallel assembly should be able to operate with less wobble and the lockup ought to be made more secure as the blade stop, and blade should move less with respect to one another.

Also distributing the friction and wear across a greater surface area should mean, all other things being equal, that the parts wear more slowly.
 
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Let's not get off track. All construction being equal, does a bigger pivot make that component stronger? The answer is Yes The same way a larger axle in a truck is stronger than a smaller axle.
This is the 'track'
Does a bigger pivot on paper actually translate into a stronger or better knife??
and the comments are spot on. If the knife already has another weak point, changing the pivot isn't going to improve the knife. You go with a stronger pivot if that is where the knife would fail first.
 
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